To Engineer Is Human: The Role Of Failure In Successful Design, by Henry Petroski
There is in this particular book a sense of the dynamic nature of engineering and the sort of tension that exists between a desire for safety and a desire to transcend previous efforts as well as economize in various practices, all of which leads to risk of failure. Using both familiar and unfamiliar examples, the author does a good job here of discussing the pivotal role of failure in leading to successful designs, revealing the paradoxical truth that learning from failure leads to future successes, while success often brings with it a strong sense of complacency that in turn leads to future failure, and that our own contemporary efforts at design are hindered by a lack of understanding of the importance of learning from history and deep problems in communicating and even understanding what is being designed because of the complexity of what is being done and the ineffectiveness of various computer models at approximating reality. The author thus shows himself to be temperamentally conservative, which is a very good thing, even as he is deeply learned in the ways that failure has shaped design and how constraints are present in any sort of design efforts.
This particular book of around 250 pages or so is full of interest and even some surprises. The author begins with an understanding that design and engineering are a part of what it means to be human (1) and that falling down is a part of growing up (2), whether one is a toddler trying to learn how to walk better or whether one is an engineer working on a bridge or vehicle design. The author then uses “The Deacon’s Masterpiece” as a way of discussing lessons about design from both play and life (3) and discusses the nature of every design as a hypothesis (4). The author discusses the importance of foreseeing failure and accounting for its possibility in leading to success (5) and that design helps us get from where we are to where we want to be (6). The author reminds us that design is often a revision of what has come before (7) in some fashion that that reality places us with accidents that are waiting to happen (8) that can wreck our plans and designs. The author discusses safety in numbers (9) as well as the problem of cracks (10), and gives a humorous story of buses and knife blades in trying to build things cheaply (11). An interlude about the success of the Crystal Palace (12) leads to a discussion of bridge failures (13) as well as the importance of forensic engineering and engineering fiction in teaching an understanding of failure (14). The author as a chance to grouse about the failure of people to understand how design used to be done in the face of the transition between slide rules and computers (15), the discussion of people as connoisseurs of chaos (16), and the limits of design (17) in addressing factors of safety and economic concerns. This version of the book then concludes with a new afterword that discusses the Challenger failure.
Why is it that engineering seems so remote from the experience of most people? After all, the basic structures that we use in design are things that are familiar to human beings seeking to interact with the world. Moreover, the attitude of learning from failure and dealing with the tension of our desires for safety and our desires for novelty as well as efficiency is something that is present in many aspects of our lives and not merely in our mechanical and structural designs. The author examines how it is that some failures, like that of the first Tacoma Narrows bridge, came about because of a failure to learn from history when it came to overly elegant bridge design that failed to take wind loads and the problem of resonance into consideration. All of this entertaining discussion is included with a wealth of humane and gentle humor that puts the reader at ease and that allows even those who have little familiarity with engineering design to understand what the author is getting at and be able to think at least a little more soundly about engineering failures and why they happen.